EP3799226A1

EP3799226A1 - Protection device for unipolar or multipolar connectors and related assembly

Info

Publication number: EP3799226A1
Application number: EP20000343.2A
Authority: EP
Inventors: Marco Pizzato; Simone Zonta
Original assignee: Pizzato Elettrica SRL
Current assignee: Pizzato Elettrica SRL
Priority date: 2019-09-25
Filing date: 2020-09-25
Publication date: 2021-03-31
Also published as: IT201900017225A1

Abstract

A protection device (100, 200, 300, 400, 500) for unipolar or multipolar connector assemblies, wherein a multipolar connector assembly (1) comprises at least one first connector (2) and at least one second connector (3) connectable in a removable to said at least one first connector (2) to move from a coupling operating condition to an uncoupled non-operative condition, wherein the protection device (100, 200, 300, 400, 500) is adapted to be applied on a connection portion (4) of said connectors (2, 3) in the operating condition to prevent their detachment and passage to the non-operating condition, which protection device comprises a first protection element (101, 201, 301, 401, 501) and a second protection element (102, 202, 302, 402, 502) provided with respective mutual coupling means, wherein the protection elements (101, 201, 301, 401, 501; 102, 202, 302, 402, 502) are designed to define, when coupled, a seat (104, 204, 304, 404, 504) for snugly fitting at least one connection portion (4) of the connectors (2, 3), the mutual coupling means being also provided with anti-tampering means to provide evidence of their possible removal.

Description

Technical Field

The present invention finds application in the field of electrical devices and particularly relates to a protection device applicable to a multipolar or unipolar connector assembly, as well as a connector assembly of the unipolar or multipolar type provided with this protection device.

State of the art

As known, unipolar or multipolar connectors are particular connection elements whose object is to create an electrical and/or data connection between a first electrical and/or electronic component or circuit and a second electrical and/or electronic component or circuit, or to a power or data network.
The unipolar or multipolar connectors currently on the market may differ from each other in various aspects, such as shape, size and number of pins.
However, in general, each connector consists of a first element associated with one of the two components and a second element associated with the other component.
The connection between the two elements of the connector can be realized by simply inserting the pin or pins of the first male element into the corresponding cavities of the second female element.
Furthermore, an external ring nut is also generally provided, which can be threaded or provided with a bayonet coupling, which has the task of making the connection stable for avoiding accidental disconnections.
Unipolar or multipolar connectors are also known which allow the connection between more than two electrical and/or electronic components or circuits and which in this case are provided with two or more male elements and/or two or more female elements.
The advantage of these connectors is represented above all by the ease of connection between the two elements, which requires a simple mechanical coupling.
In this way, the connection between the components to be connected is immediate and much simpler than the typical wiring operations, allowing the same to quickly disconnect the parts.
A negative aspect related to this simplicity of connection is represented by the ease in performing the separation between the two elements that make up the connector.
It follows that these connectors are not adequately protected from actions aimed at separating their components, be they involuntary or due to negligence or deliberately irregular actions of an operator.
As matter of fact, in the event that one of the two devices is a safety device of a machine or plant, this type of connection does not prevent an operator from wanting to bypass the safety device by disconnecting it and making an appropriate electrical connection that simulates the presence of the device itself.
FR2755798 discloses a protection for multipolar connectors applicable to a specific typology of connectors and which is adapted to prevent accidental openings between the two elements of the connector.
However, this protection, in addition to being configured to be applied to a type of connector that is no longer available, is not effective against voluntary attempts to remove the connection.
It also does not provide evidence of any attempts to remove the connection, even making it possible to remove the protection to temporarily disconnect the two elements of the connector and then reconnect them and reapply the protection. US2012/252258A1 discloses a protection for connecting elements of electric cables provided with a rib break system which allows, once it has been pressed, that the connecting ring nuts of the connectors may engage with each other by friction and unscrew.
This feature constitutes a limit since, in particular in the connections between a flying connector and a panel connector, the connector could be unscrewed without leaving a trace.
Furthermore, the use of two mutually hinged and non-divisible half-shells makes it difficult to apply the protection in devices that have already been mounted and wherein the connectors are very close to a wall, not allowing to have the space needed to insert the protection on and hook the teeth thereof.
US7798837B1 discloses a further protection for connectors formed by two mutually hinged half-shells and which is not provided with an integrated anti-burglary system. To signal a possible break-in, it is instead necessary to provide an adhesive applied at the junction line of the two half-shells once closed.
In US2010/255724 a protection for connectors is disclosed which provides for the possibility of opening and removal by means of a special tool adapted to release a retaining clip, allowing to release the connectors without leaving a mark on the protection.

Scope of the invention

The object of the present invention is to overcome the above drawbacks by providing a protection device for unipolar or multipolar connectors which is characterized by high efficiency and relative cost effectiveness.
A particular object is to provide a protection device for unipolar or multipolar connectors which prevents voluntary opening of the connector which it is applied to. Still another particular object is to provide a protection device for unipolar or multipolar connectors which avoid unauthorized attempts to remove the connection between the elements of the connector, providing evidence of such attempts.
Still another particular object is to provide a protection device for unipolar or multipolar connectors which can no longer be reapplied, at least in an integral way, if it is removed by an unauthorized person.
Still another particular object is to provide a protection device for unipolar or multipolar connectors which may also be applied to pairs of connectors already connected to each other and in conditions of limited space, as in the case of connectors placed against a wall.
These objects, as well as others which will become more apparent hereinafter, are achieved by a protection device for unipolar or multipolar connectors which, according to claim 1, comprises at least one first connector adapted to be connected to a first electrical or electronic component or circuit, at least one second connector adapted to be connected to a second electrical or electronic component or circuit and removably connectable to said at least one first connector to move from an operative coupling condition to a non-operative decoupled condition, a protection device adapted to be applied on a connection portion of said connectors in said operative condition to prevent its detachment and passage into said non-operative condition.
According to a peculiar feature of the invention, the protection device is adapted to move from an open configuration to a closed configuration wherein it defines a seat snugly fitting at least one portion of said connectors, said protection device being also provided with anti-tampering means suitable to provide evidence of the opening thereof starting from said closed configuration.
Preferably, the anti- tampering means may be designed to prevent the restoration of said closed configuration after passing into said open configuration.
Thanks to this combination of features, the protection device will be constantly positioned on the connection portion of the connectors to prevent access thereto, so as to avoid accidental detachment thereof.
Furthermore, the presence of the anti-tampering means will prevent the two connectors from being uncoupled and possibly their subsequent re-coupling without there being evidence of such an action.
Furthermore, the protection device will prevent the two connectors from being deliberately decoupled and in particular will make inaccessible the threaded ring nut, which in common connectors has the task of mechanically locking the connection between the two connectors.
Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief disclosure of the drawings

Further features and advantages of the invention will become more apparent in the light of the detailed description of preferred but not exclusive embodiments of a protection device for multipolar or unipolar connectors and of an assembly provided with the protection device according to the invention, illustrated by way of nonlimiting example with the aid of the attached drawing tables wherein:

FIG. 1 is a perspective view of a protection device in a first preferred embodiment and in an open condition;
FIG. 2 is a perspective view of the protection device of Fig. 1 in the closed condition;
FIG. 3 is a perspective view of a protection device in a second preferred embodiment and in the open condition;
FIG. 4 is a perspective view of the protection device of Fig. 3 in closed configuration;
FIG. 5 is a perspective view of a multipolar connector assembly provided with the protection device of Fig. 3 in the open condition;
FIG. 6 is a perspective view of the assembly of Fig. 5 with the protection device in the closed operating condition;
FIG. 7 is a first side view of the assembly of Fig. 6;
FIG. 8 is a sectional view of the assembly according to the A-A plane of Fig. 7;
FIG. 9 is a second side view of the assembly of Fig. 6;
FIG. 10 is a sectional view of the assembly according to the B-B plane of Fig. 9;
FIG. 11 is a perspective view of a variant of the protection device of Fig. 3 in the open condition;
FIG. 12 is a perspective view of the protection device of Fig. 11 in the closed condition;
FIG. 13 is a perspective view of a multipolar connector assembly provided with the protection device of Fig. 11 in open configuration;
FIG. 14 is a perspective view of the assembly of Fig. 13 with the protection device in closed operating condition;
FIG. 15 is a perspective view of a multipolar connector assembly provided with a protection device in a fourth preferred embodiment and in an open configuration;
FIG. 16 is a perspective view of the assembly of Fig. 15 with the protection device in the closed operating condition;
FIG. 17 is a first side view of the assembly of Fig. 16;
FIG. 18 is a sectional view of the assembly according to the D-D plane of Fig. 17;
FIG. 19 is a second side view of the assembly of Fig. 16;
FIG. 20 is a sectional view of the assembly according to the E-E plane of Fig. 19;
FIG. 21 is a perspective view of a multipole connector assembly provided with a protection device in a fifth preferred embodiment and in an open configuration;
FIG. 22 is a perspective view of the assembly of Fig. 21 with the protection device in the closed operating condition;
FIG. 23 is a first side view of the assembly of Fig. 22;
FIG. 24 is a sectional view of the assembly of Fig. 22 according to the F-F plane of Fig. 23;
FIG. 25 is a second side view of the assembly of Fig. 22;
FIG. 26 is a sectional view of the assembly of Fig. 22 according to the F-F plane of Fig. 25.

Best modes of carrying out the invention

With reference to the attached figures, some preferred but not exclusive embodiments of a protection device for unipolar or multipolar connectors and a multipolar connector assembly provided with a protection device according to the invention are shown.
It should be noted that, even if the embodiments of the figures illustrate connector assemblies of the multipolar type, the protection device can be applied in an absolutely identical manner also to connector assemblies of the unipolar type.
It is also specified that the connector assembly may be of any type and for any application, both within civil and industrial systems, for the connection of any type of component, device, circuit or electrical and/or electronic system.
In particular, the assembly may be designed both for the connection between two or more electrical and/or electronic devices and/or equipment and for the connection of two or more electrical and or electronic cables.
Therefore, it is clear that the connector assembly shown in the figures is only one of the many assemblies that may be used in association with the protection device of the invention.
In its most general form, the multipolar connector assembly, indicated globally with 1, comprises a first connector 2 suitable for being connected to a first electrical or electronic component or circuit C, and a second connector 3 suitable for being connected to a second component or electric or electronic circuit, not shown, and connectable in a known manner in a removable manner to the first connector 2 to move from an inoperative uncoupled condition to an operative condition of coupling wherein the two connectors 2, 3 define a connection portion 4.
In the shown embodiments, the first connector 2 constitutes the male element of the coupling while the second connector 3 defines the female element. However, this definition is only an example since it will also be possible to realize different coupling modes between the two connectors 2, 3.
Typically for this type of connector, one of the two connectors 2, 3 is provided with a ring nut 5, for example of the threaded type or with bayonet coupling, the purpose of which will be to make stable the mechanical coupling between the two connectors 2, 3 once the pin or the pins of the first male connector 2 have been inserted into the cavities of the second female connector 3, according to known methods and therefore not described in more detail.
In the illustrated embodiments, which represent one of the most common shapes for unipolar or multipolar connectors, net of possible differences in the dimensions and some variants of lesser importance, the connectors 2, 3 comprise respective substantially cylindrical end portions to define a connection portion 4 also substantially cylindrical.
However, it will also be possible to have connectors of different shapes, for example with a quadrangular section or other prismatic shape.
Fig. 1 shows a first preferred but not exclusive embodiment of the protection device, globally indicated with 100, suitable to be applied on the connection portion 4 of the connectors 2, 3 so that, in the operating condition, it covers and makes inaccessible the possible ring nut 5 to prevent the release thereof and prevent the detachment of the connectors 2, 3 and the passage of the assembly 1 in the open non-operative condition. In particular, the protection device 100 comprises a first protection element 101 and a second protection element 102 provided with respective mutual coupling means.
The two protection elements 101, 102 are mutually joined by means of a flexible band 103 which allows them to be separated without complete detachment.
Furthermore, the two protection elements 101, 102 are designed to define, when coupled as in Fig. 2 , a seat 104 for the snugly fitting of at least one portion of the connectors 2, 3 and in particular of the connection portion 4 provided of the ring nut 5 defined above, so that the device 100 in the closed condition completely wraps the connection portion 4.
The mutual coupling means are also provided with anti-tampering means adapted to provide evidence of their possible removal starting from the closed configuration and of a possible detachment of the two protection elements 101, 102.
Conveniently, the anti-tampering means will be designed to prevent their re-insertion after their removal and the consequent restoration of the closed configuration following the passage of the device 100 into the open configuration.
Conveniently, the two protection elements 101, 102 are shaped to define, once coupled, a housing seat 104 for the connection portion 4 of the male 2 and female 3 connectors. Each of the two protection elements 101, 102 has a circular recess 105 on each of its side walls to follow the profile of the connectors 2, 3 in the closed operating condition. The coupling means are defined by a tab 106 associated with one of the two protection elements 101 and by a slot 107 provided in the other protection element 102 and adapted to receive and hold the tab 106 preventing its removal without damaging at least one of the two hooking elements or other part of the device 100.
For example, in a not shown manner, the anti-tampering means may be integral with the two coupling elements 106, 107 and be defined by pairs of teeth adapted to cooperate with each other to block the coupling.
Fig. 3 shows a second embodiment of the protection device, generally indicated with 200 which consists of two protection elements 201, 202 designed to be completely separated from each other when they are in the open condition.
This configuration will have the advantage of allowing the application of the protection device even in conditions of limited space, such as in the case of connectors placed against a wall.
Also in this case, the protection device 200 comprises a first protection element 201 and a second protection element 202 provided with respective mutual coupling means to be mutually joined and move from the open to the closed operating condition of Fig. 4 wherein they will cover the connection portion 4 of the assembly 1, possibly provided with the ring nut 5, as shown in Fig. 6 .
The two protection elements 201, 202 are designed to define, when coupled, a seat 204 for snugly fitting the connection portion 4 provided with the ring nut 5 defined above. The coupling means are defined by a pair of tabs 206 and by a pair of slots 207 associated with each of the two protection elements 201, 202 so that each tab 206 is inserted into the opposite slot 207.
Also in this embodiment, the mutual coupling means are provided with anti-tampering means suitable to provide evidence of their possible removal starting from the closed configuration and of a possible detachment of the two protection elements 201, 202, always preventing their re-insertion after their removal and consequent restoration of the closed configuration after the passage of the device 200 into the open configuration.
As more clearly visible from Fig. 8 , the anti-tampering means comprise, for each tab, a slot 208 adapted to be snapped into place by a corresponding tooth 209 provided in the corresponding slot 207 so that it cannot be removed without damaging one of the parts.
From Fig. 10 it can also be seen that the second connector 3 has a groove 6 which delimits the connecting portion 4 on one side and which is designed to receive one of the semicircular recesses 205 of the protection elements 201, 202.
The groove 6 will define a means for limiting the relative sliding between the protection device 200 and the connectors 2, 3 for blocking or limiting the sliding of the protection device 200 on the connection portion 4 along the axial direction L. Figs. 11 to 13 shows a third embodiment of the protection device according to the invention, globally indicated with 300, which differs from the previous one essentially in that it has a larger axial dimension in order to be applied to a connector assembly composed of connectors 2, 3 of the flying type.
Also in this case, the protection device 300 consists of two protection elements 301, 302 designed to be completely separated from each other when they are in the open condition and provided with respective mutual coupling means to be mutually joined and move from the open condition of Fig. 13 to the closed operative one of Fig. 14 in which they will cover the connection portion 4 of the assembly 1, possibly provided with the ring nut 5.
The two protection elements 301, 302 are designed to define, when coupled, a seat 304 for snugly fitting the connection portion 4.
Also in this case the coupling means are defined by a pair of tabs 306 provided with respective slots 308 and by a pair of slots 307 having respective teeth 309 adapted to be inserted into the corresponding slots 307 to operate as anti-tampering means. Also in this case it is also observed that the second connector 3 has a groove 6 which delimits the connecting portion 4 on one side and which is designed to receive one of the semicircular recesses 305 of the protection elements 301, 302.
Fig. 15 shows a fourth embodiment of the protection device, indicated globally with 400, which comprises two protection elements 401, 402 adapted to be applied around the connection portion 4 and each having a shaped recess 409 so that, when the protection device 400 is in assembled condition, the recesses 405 entirely envelop the connection portion 4, as visible in Fig. 16 .
The two protection elements 401, 402 are designed to define, when coupled, a seat 404 for snugly fitting the connection portion 4.
Each of the two protection elements 401, 402 is also provided with both coupling means and centering means to allow a stable but removable coupling.
By removable coupling it is meant that the two protection elements 401, 402 may be decoupled from each other in order to be subsequently coupled again; moreover, in the event that the anti-tampering means are not applied, the coupling and uncoupling between the two protection elements 401, 402 may also be carried out for a large number of times without the device 400 being damaged.
As more clearly visible from Fig. 15 , one of the two protection elements 401 comprises two pins 410 adapted to fit into corresponding blind holes 411 of the other coupling element 402 to operate as centering element during the closing step.
The coupling means, on the other hand, are defined by a further pair of holes 412, 413, one for each of the protection elements 401, 402, at least one of which will be pass through, and by a screw 414 or similar fastening member suitable for inserting into the holes 412, 413.
In the illustrated embodiment, the two holes 412, 413 are adapted to be aligned with each other along a direction transverse to the axial direction L defined by the connection portion 4 of the connectors 2, 3 for the insertion of the screw 414 always in the radial direction.
According to a variant not shown, the holes 412, 413 may extend axially to insert the screw 414 also in an axial position, i.e. parallel to the main development of the connectors 2, 3.
The anti-tampering means comprise an anti-tampering cap 415 designed to be inserted to measure in the through hole 412 at its open end facing outwards to close it and prevent access to the corresponding fastening member 414 from the outside.
In this way it will not be possible to remove the cap 415 to access the fastening member 414 to remove it and proceed with the decoupling between the two protection elements 401, 402 without leaving a trace of such an action.
Preferably, the anti-tampering cap 415 may be inserted at measure in the corresponding through hole 412 so as not to present any element that may facilitate its extraction, as more clearly visible from Fig. 18 .
Furthermore, the anti-tampering cap 415 may be designed to break or be damaged if it should be removed, so as to prevent its re-insertion or in any case give immediate evidence of the attempted removal.
The anti-tampering cap 415 may be internally hollow to also insert a connection member having a non-flat head and larger in size than in the figures.
As can be seen from Fig. 20 , the second connector 3 has a groove 6 which delimits the connection portion 4 on one side and which is designed to accommodate the semicircular recesses 405 of the protection elements 401, 402.
The groove 6 will define a constraint means for relative sliding between the protection device 400 and the connectors 2, 3 to block or limit the sliding of the protection device 400 on the connection portion 4 along the axial direction L.
Fig. 21 shows a fifth preferred but not exclusive embodiment of the protection device, globally indicated with 500, associated with the same multipolar connector 1 of the previous embodiment.
In particular, Fig. 21 shows the device 500 in the inoperative position, while in Fig. 22 the protection device 500 is illustrated in the assembled operating configuration. Also in this case, the protection device 500 consists of two protection elements 501, 502 adapted to be placed above the connectors 2, 3 to completely wrap the connection portion 4, defining a housing seat 504 for the connection portion 4.
Each protection element 501, 502 is provided with coupling means and anti-tampering means.
In this case, a first protection element 501 comprises a pair of tabs 506 adapted to snap into corresponding slots 507 present in the other protection element 502.
Moreover, each of the tabs 506 comprises a first retaining tooth 518 adapted to interact with a corresponding second retaining tooth 519 present in the corresponding slot 507 to define the anti-tampering means.
In particular, the tabs 506 and/or the internal walls of the slots 507 may be designed to break following their bending if there is an attempt to disengage the pairs of retaining teeth 518, 519, for example by means of a screwdriver or similar tool.
Also in this case, as visible in Fig. 26 , each of the protection elements 501, 502 will be provided with a semicircular recess 505 which will enter the groove 6 present in the second connector 3 to operate as a means of limiting the relative sliding between the protection device 500 and connectors 2, 3.
It should be noted that, for all the illustrated embodiments, the position of the connectors 2, 3 may also be inverted with respect to the figures and that the groove 6 may also be made on the first connector 2.
The connector assembly and the protection device according to the invention are susceptible of numerous modifications and variations, all falling within the inventive concept expressed in the attached claims All the details can be replaced by other technically equivalent elements and the materials can be different according to the requirements, without departing from the scope of protection of the present invention.

Claims

A protection device (100, 200, 300, 400, 500) for unipolar or multipolar connector assemblies, wherein a multipolar connector assembly (1) comprises at least one first connector (2) adapted to be connected to a first component or electric or electronic circuit and at least one second connector (3) adapted to be connected to a second component or electrical or electronic circuit and removably connectable to said at least one first connector (2) to move from an operative coupling condition to a non-operative decoupled condition, wherein the protection device (100, 200, 300, 400, 500) is adapted to be applied on a connecting portion (4) of said connectors (2, 3) in said operative condition to prevent the decoupling thereof and the passage in said non-operative condition, which protection device comprises:
- a first protection element (101, 201, 301, 401, 501) and a second protection element (102, 202, 302, 402, 502) provided with respective mutual coupling means to move from a closed operative configuration to an open non-operative configuration and vice versa;
characterized in that said protection elements (101, 201, 301, 401, 501; 102, 202, 302, 402, 502) are designed to define, when coupled, a seat (104, 204, 304, 404, 504) for housing at least one connecting portion (4) of said connectors (2, 3), said mutual coupling means being designed to hold said protection elements (101, 201, 301, 401, 501; 102, 202, 302, 402, 502) monolithic with each other and being further provided with anti-tampering means suitable to provide evidence of their possible removal.
Device as claimed in claim 1, characterized in that said anti-tampering means are designed to prevent the restoration of said closed configuration after the passage in said open configuration.
Device as claimed in claim 1 or 2, characterized in that said protection device (100, 200, 300, 400, 500) comprises a first protection element (101, 201, 301, 401, 501) and a second protection element (102, 202, 302, 402, 502) provided with respective mutual coupling means and designed to define, when coupled, said housing seat (104, 204, 304, 404, 504) of said at least one connecting portion (4) of each of said connectors (2, 3).
Device as claimed in any preceding claim, characterized in that said coupling means comprise at least one male coupling element (106, 206, 306, 506) associated with one of said protection elements (101, 201, 301, 501) and at least one female coupling element (107, 207, 307, 507) associated with the other of said protection elements (102, 202, 302, 502) to couple with a corresponding male coupling element (106, 206, 306, 506).
Device as claimed in claim 4, characterized in that said anti-tampering means are integral with said coupling means and comprise for each of said female coupling elements (207, 307) a retaining tooth (209, 309) adapted to engage a corresponding slot (208, 308) present in the corresponding male coupling element (206, 306).
Device as claimed in claim 4, characterized in that said anti-tampering means are integral with said hooking means and comprise for each of said male coupling elements (506) a first retaining tooth (518) adapted to interact with a corresponding second retaining tooth (519) associated with the female coupling element (507).
Device as claimed in any claims from 1 to 3, characterized in that said coupling means comprise at least one hole (412, 413) for each of said protection elements (101, 201, 301, 401, 501; 102, 202, 302, 402, 502), said holes (412, 413) being adapted to be aligned with each other and at least one of them being passing-through for the insertion of a screw or similar fastening member (414).
Device as claimed in claim 7, characterized in that said anti-tampering means comprise at least one burglar-proof plug (415) adapted to be snugly fitted in said passing-through hole (412) at its open end facing outwards to close it and preventing access from the outside to said fastening member (414).
A unipolar or multipolar connector assembly with protection device, comprising:
- at least one first connector (2) adapted to be connected to a first component or electrical or electronic circuit (C);

- at least one second connector (3) adapted to be connected to a second component or electrical or electronic circuit and removably connectable to said at least one first connector (2) to pass from an operative coupling condition to an inoperative decoupled condition;

- a protection device (100, 200, 300, 400, 500) adapted to be applied on a connecting portion (4) of said connectors (2, 3) in said operative condition to prevent them from being detached and moving into said non-operative condition;
characterized in that said protection device (100, 200, 300, 400, 500) is adapted to move from an open configuration to a closed configuration in which it defines a seat (104, 204, 304, 404, 504) for housing at least one connecting portion (4) of said connectors (2, 3), said protection device (100, 200, 300, 400, 500) further being provided with anti-tampering means adapted to provide evidence of its opening starting from said closed configuration.
Assembly as claimed in claim 9, characterized by comprising means for limiting the relative sliding between said protection device (100, 200, 300, 400, 500) and said connecting portion (4) along an axial direction (L), at least one of said connectors (2, 3) having a radial groove (6) and each of said protection elements (101, 201, 301, 401, 501; 102, 202, 302, 402, 502) comprising at least one recess (105, 205, 305, 405, 505) adapted to be inserted into said groove (6).